This application is a U.S. National Phase Application under 35 U.S.C. §371 and claims the benefit of priority to PCT Application Serial No. PCT/US2013/078266, filed on Dec. 30, 2013 and entitled “Well Fluid Sampling Confirmation and Analysis”, which claims priority to U.S. Provisional Application Ser. No. 61/878,243, filed on Sep. 16, 2013 and entitled “Well Fluid Sampling Confirmation and In-Situ Analysis”, the contents of which are hereby incorporated by reference.
This disclosure relates, in general, to testing and evaluation of subterranean formation fluids.
In drilling subterranean wells, testing is performed to obtain a fluid sample from the formation to, among other things, determine the composition of the formation fluids. In this testing, efforts are taken to obtain a sample of the formation fluid that is representative of the fluids as they exist in the formation. In a typical sampling procedure, a sample of the formation fluids may be obtained by lowering a sampling tool having a sampling chamber into the wellbore on a conveyance, such as a wireline, slick line, coiled tubing, jointed tubing or the like. When the sampling tool reaches the desired depth, one or more ports are opened to allow collection of the formation fluids. Once the ports are opened, formation fluids travel through the ports and a sample of the formation fluids are collected within a sampling chamber of the sampling tool. After the sample has been collected, the sampling tool is withdrawn from the wellbore so that the formation fluid sample may be analyzed.
As the fluid sample is retrieved to the surface, the temperature of the fluid sample tends to decrease causing shrinkage of the fluid sample and a reduction in the pressure of the fluid sample. These changes can cause the fluid sample to approach or reach saturation pressure, creating the possibility of flashing entrained gasses present in the fluid sample and subsequent asphaltene deposition. Once such a process occurs, the resulting fluid sample is no longer representative of the fluids present in the formation. Therefore, a need has arisen for obtaining a fluid sample from a formation without degradation of the sample during retrieval of the sampling tool from the wellbore. A need has also arisen for maintaining the integrity of the fluid sample during storage on the surface
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